I've been looking into the evidence of the health effects of sucrose or similar glucose-fructose mixtures found in fruit compared to glucose or starch.
There's seems to be a fair amount of evidence that fructose can be bad, but most of the commonly cited studies for this opinion use fructose only (not fructose and glucose together). Are there any studies that compared glucose or starch to fructose-glucose or sucrose? Preferably as performed on humans?
I'd especially enjoy seeing a study on the effects of equal calories of a fruit versus a tuber.
"Consuming fructose-sweetened, not glucose-sweetened, beverages increases visceral adiposity and lipids and decreases insulin sensitivity in overweight/obese humans"
Its not a study on sucrose, but it compares fructose with glucose, which amounts to a similar thing as what you want. In think theres quite a few studies linking fructose to visceral fat.
Okay, here are a few things I looked at:
I found a few studies that suggest sucrose raises triglycerides compared to starch, including these two:
Since sucrose doesn't increase HDL, this might be bad because it would mean an increased ratio of triglycerides to HDL, which appears to be a marker of heart disease risk:
However, I also found three studies which had slightly different findings than the first two:
In the first study, when starch replaced sucrose in the diet of 5 subjects, triglycerides increased in 3 subjects and decreased in the other 2. Interestingly, the patients with the highest trigs were the ones who saw decreases on the starch diet. In the other three studies, no significant differences in triglcyeride concentrations were seen between sucrose and starch or maltose (which is form of glucose).
So sucrose may increase triglycerides compared to starch, or it may do nothing or even decrease them.
I also found some studies on the effects of glucose and sucrose during exercise:
The first study gave twelve subjects water with sucrose, glucose, or fructose during 115 minutes of exercise on stationary bikes. Sucrose and glucose produced equal effects on things like cortisol levels, cycling speed, perceived exertion, and gastronomical distress. Fructose, meanwhile, performed poorly by comparison.
The second study gave 10-14 year old boys either water, glucose, or a 50-50 mixture of glucose and fructose during exercise (also on stationary bikes). The glucose and glucose-fructose both outperformed the water on things like VO2 and time to exhaustion, with no significant different difference between the two (actually, only the fructose-glucose group had a time to exhaustion that was significantly greater than water).
Finally, the third study is a review article that concluded "No apparent differences exist between glucose, sucrose, or maltodextrins in their ability to improve (exercise) performance. Ingesting fructose during exercise, however, does not improve performance and may cause gastrointestinal distress".
I also found some studies on sucrose and glucose on glycogen levels:
The first study fed subjects various sugar containing drinks during exercise and found that sucrose and glucose refill muscle glycogen to an equal degree (sucrose filled glycogen more, but it wasn't statistically significant).
The second study gave soccer players drinks containing glucose, a mixture of 66% glucose and 33% fructose, or a placebo during exercise. No differences were observed between the glucose and glucose-fructose groups, although the glucose-fructose group had greater exercise capacity and higher post workout glycogen levels, the difference wasn't statistically significant.
Finally, the third study is a review article which concluded "Ingestion of glucose or sucrose results in similar muscle glycogen resynthesis rates".
So it looks like, at least for exercise, sucrose and glucose appear to be equal.
I found two studies which suggest sugar does not differ from starch for weight loss and weight maintenance when calories are equal:
In the first study, subjects were placed on isocaloric low calorie diets for weight loss. One diet contained 43% of calories as sucrose while the other diet replaced that sugar with starches such as bread and rice. At the end of the diet trial, both groups lost an equal amount of weight (including an equal amount of belly fat loss) and no difference in energy expenditure were found.
In study number two, subjects were given equal calorie diets containing either 10% or 25% sucrose, with the difference being made up largely by starch. An insignificant amount of weight was lost, with no difference between the two groups. Once again, when calories and nutrients are controlled, the effects of sugar and starch on body weight appears to be the same.
Also, energy expenditure has been shown to increase more after consuming sugar than consuming starch:
So sucrose does not appear to have any worse effects on weight than starch during weight loss and weight maintenance when calories are equal.
I found some studies which saw mixed effects of the exchange of sugar and starch:
In the first study, sucrose appeared to cause worse effects on insulin resistance than starch, although I think the effect looks rather small. In the second study sucrose again appeared to worsen insulin resistance as it also apparently increased blood glucose levels (I cant find the full text for this study, so I don't have the details). Still, the third study found no such effect on blood glucose levels or apparent insulin resistance between sucrose and starch.
So it does appear that sugar may be worse for insulin resistance than starch, but its hard to say how strong of an effect it is.
These were but a few variables I look, but I was honestly pretty surprised that starch didn't outperform sucrose more significantly. It does look like starch came out ahead, but to the degree I would have expected. I've come to the conclusion that fructose gets way over demonized when an equal or greater amount of glucose comes along with it.
Doesn't matter - we break down sucrose using an enzyme called sucrase.
Sucrase breaks sucrose down into glucose and fructose in the presence of water and acid (available in via stomach and digestive tract). In the end, if you eat sugar, it'll get converted into glucose, and fructose. It's (almost) the same as eating them separately. I say almost because if you eat them separately, they'll just get less processed, so you'll use less enzymes to absorb them.
So the fructose will still have the same effect it normally does on your liver.
You'll be hard pressed to find any commercial products sweetened with dextrose (glucose) vs plain sucrose, (or worse high fructose corn syrup, agave syrup, etc.)
Best to avoid the whole thing by not ingesting the stuff.
I think you already have these links from another post, but i can't find it now, so i'll put them up just in case.
Not sure how relevant they are to your question, but there may be some helpful bits & pieces in there.
& it is only applicable to a diet that is deficient in choline and methionine (i think).
(& they are studies on rodents).
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2739762/ "Dietary sucrose is essential to the development of liver injury in the methionine-choline-deficient model of steatohepatitis"
"Overall, the results indicate that dietary sucrose is critical to the pathogenesis of MCD-mediated steatohepatitis"
& discussed here http://blog.cholesterol-and-health.com/2010/11/sweet-truth-about-liver-and-egg-yolks.html & here http://blog.cholesterol-and-health.com/2010/11/they-did-same-thing-to-lab-rats-that.html
I found a few studies that suggest sucrose raises triglycerides compares to starch, including these two:
Since sucrose doesn't increase HDL, this might be bad because it would mean an increased ratio of triglycerides to HDL, which appears to be a marker of heart disease risk.
However, I found another study which had slightly different findings:
When starch replaced sucrose in the diet of 5 subjects, triglycerides increased in 3 subjects and decreased in the other 2. Interestingly, the patients with the highest trigs were the ones who saw decreases on the starch diet.
So sucrose may increase triglycerides compared to starch, but it may even decrease them.
I've as of yet not been able to find much else, but I'm still looking. Anyone else have evidence that sugar is worse than starch?
This doesn't really answer your question very well, but anecdotally and also observationally, a given amount of starch seems to preferable to a given amount of fruit, ceteris paribus, when one has both body composition (maximizing the muscle/body fat ratio) and glycolytic performance (such as weight training and sprinting) in mind. I say this only based upon personal experimentation as well as speaking personally with some prominent fitness and modeling professionals.
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